Train control system



Qct. 1, 1940. w. B. WAIT TRAIN CONTROL SYSTEM Filed Oct. 8, 1938 mm R Y 0W .E W muvmm Ef 0 W5 T I M M w 6 Z 0 2 Patented a. 1, 194;

' UNITED STATES PATENT -or fice.

9 Claims.

This invention relates to improvements in train control systems and especially to means for controlling forestalling of the automatic application of brakes when the brakes are subject to 6 control of a wayside signal.

In known train control systems comprising electrical or mechanical apparatus controlled either electrically or mechanically from the wayside block signal system the air-brake valve on 10 the locomotive is automatically actuated when the wayside signal is other than clear which demands cautionary speed reduction or stopping of the train. These systems generally include an acknowledging or forestalling lever which can be used by the engineman to prevent the automatic operation of the air-brake control valve. Provision is made whereby the forestalling lever may be operated to forestall automatic application of the brake only during a period of predetermined so time prior to passing the wayside signal. If the forestalling lever is used and held before said period begins, the brake valve will be automatically operated by control of the forestalling lever. If used and held during said period automatic I operation of the air-brake control valve under control of the wayside signal will'be prevented and the train may be controlled in the usual manner. If the forestalling lever is not operated during this period, then the air-brake valve will 80 be automatically actuated and the locomotive and train will be brought to a stop. Before the brakes can be released it is necessary for a member of the engine crewto leave the cab and walk to the rear of the tender and reset the train con- 85 trol apparatus before the brakes may be released.

Forestalling as described is based on the premise that if the engineman acknowledges and forestalls, he is alert and able to perform the required functions necessary to operate the loco- 40 motive and braking apparatus according to prescribed practice. I

In practice it has sometimes. occurred that an engineman would forestall the automatic application of the brakes and run past the yellow 45 signal, expecting that the block would clear and that the next signal would be yellow and not red.

If the next signal encountered is also yellow, he

may again similarly forestall" and so run from block to block on the yellow without slowing the 50 speed of the tra Such practice is found to be undesirable fo the brakes. This has been known' to occur. If

- the train is travelling at a high rate of speed this practice of forestaliing is or may be very dangerous and has been known to be followed b disastrous consequences, involving the loss of life I and injury to property.

On the other hand, if the train be moving at a slow rate of speed when the engineer forestalls at the yellow, forestalling' may be accomplished with safety, dependent on the length 10 of the blocks and the curvature of the line which may hide from the sight of the engineer all but a short distance of track ahead of him.

Knowing the speed at which an engineman might forestall with the possibility of stopping 1 his train before running into the next block if the signal turns out to be red, would make it possible to lay down a definite rule of action in such cases which, however, within the safety limits above referred to, would leave the matter of foretalling in the judgment of the engine man.

The diificulty with the application of such a rule by the engineman is that, left to his unguided judgment, he frequently is not able to ac- 25 curately estimate the speed and; again using his best judgment, he might forestall" at a speed exceding the speed beyond which forestalllng is interdlcted.

' One of the objects-of my invention is the pro- 30 vision of mechanism whereby the automatic operation of the air-brake control valve can be forestalled only when the train is traveling below a predetermined rate. This object may be carried out by electrical or mechanical means, either by rendering the operation of the forestalling lever ineffective or by preventing an operation of the forestalling lever, at speeds above the predetermined rate.

Another object of my invention is to provide m means controlled by a speedometer or other speed responsive or speed controlled means on the locomotive for opening the forestalling circuits and maintaining the same open whfle the train runs at speeds above the predetermined rate.

Another object of the invention is to provide means controlled by the speedometer. or other speed responsive or speed controlled means on the locomotive for locking the forestalling lever against operation when the locomotive is traveling at a' speed above the predetermined rate.

. Another object of the invention is to associate with the acknowledging mechanism a graphic pen or the like adapted to make a mark on a tape upon which is recorded the speed of the locomotive, whereby a mark is made on the tape when the acknowledging lever is operated whether the same is effective or ineflective.

Another object is the provision oi a signal automatically operated under contrpl ot the speed or the train to indicate whendorestalling may be effected.

Other objects of the invention will appear from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a diagram of an automatic train control system with which my improvements may be associated showing one embodiment of my invention associated therewith; and V Fig. 2 is a diagrammatic view of a second embodiment of my invention.

For purposes of illustration, I have disclosed diagrammatically a known system for controlling trains. This system comprises inductors I under control of a wayside block signal system, a receiver REC supported on the locomotive, control relays RI, R2 and R3, and an electro-pneumatic valve EPV to apply the brakes to the train. This system also includes a reset contactor RC by means of which the system may be adjusted for operation after the same has functioned to apply the brakes. The mechanism also includes an acknowledging and .forestalling lever FL by means of which the automatic operation of the electro-pneumatic valve EPV may be forestalled.

The control relays RI, R2 and R3 and the electro-pneumatic valve EPV are normally energized. The forestalling lever FL is provided with switches X, Y and Z of which X and Y are normally open and switch Z is normally closed.

The primary coil P of the receiver REC and the primary control relay R3 are energized by curent flowing from the positive side of the generator G through contact 3 of relay R2, contacts 6 and I of relay R3, ballast lamps L,L, primary coil P of receiver REC, to the negative side of the generator G.

,The primary control relay RI and secondary coil S of the receiver REC are energized by the drop in voltage across the coils of relay R3 by current flowing from the right hand side of the coils of relay R3, through contact I of relay RI, secondary coil S of receiver REC, coils of relay RI, back to the left hand side of the coils of relay R3.

The relay R2 is energized by current flowing from the positive side of the generator G, over contact 3 of relay R2, contacts 6 and l of relay R3, contact 2 of relay RI, coils of relay R2, to the negative side of the generator G.

The electro-pneumatic valve EPV is energized by current flowing from the positive side of the generator G, over contact 3 of relay R2, contacts 8 and l of relay R3, contact 8 of reset contactor RC, closed switch Z of the acknowledging or forestalling lever FL, coils of the electro-pneumatic valve EPV to the negative side of the generator G.

When the receiver REC passes over an inductor I the coils of which are closed as in the case where the wayside signal is clear, the current through the primary control relay RI is not changed sufficiently to release this relay. When under the control of the wayside signal the coils of the inductor are opened as in the case where the signal is not clear, the current through the coils of relay RI is decreased suiliciently to open its contacts. The opening of contact 2 of relay RI opens the circuit of relay R2, opening of contact 3 of relay R2 opens the circuit oi. relay R3,

braking device rendered ineffective.

and opening 0! contacts I and I of relay R3 opens the circuit of the electro-pneumatic.v valve EPV resulting In a full service application of the brakes.

To reenergize the electro-pneumatic valve EPV. it will be necessary to reenergize the relay RI. By operating the reset contactor RC, current will flow from the positive side of the generator G, over contact 0 of the reset contactor RC, across the coils of relay R2, ballast lamp L,L, primary coil 'P of the receiver REC, back to the negative side of the generator G. This produces a drop in voltage across the coils of relay R2, so that relay RI will be energized by current from the right hand side of the coils oi relay R3, through contact I0 of the reset contactor RC, across the coils of relay RI and back to the left hand side of the coils of relay R3.

Relay R2 will be energized by current over contact 2 of relay RI, closing contact 3 thereby permitting return of reset contact RC to normal which closes contact 8 and reestablishes the operating circuit of the electro-pneumatic valve EPV. The control system has been operated under control of the waysidesignal and restored to normal.

If at the time the receiver REC passes over the inductor I, the acknowledging or forestalling lever FL is operated, switch X on the acknowledging contactor is closed and relay R3 will not release as it is held energized by current from the positive side of the generator G over switch X, contacts 6 and I of relay R3, coils of relay R3, ballast lamps LL, primary coll P of receiver REC, to the negative side of generator G. With contact 3 of relay R2 open, the whistle valve WV is operated, when the receiver REC passes over the inductor I, and the relay RI will be released but will immediately be reenergized under control oi energized relay R3. Opening of relay RI causes rel after relay R2 is opened, with switch Y of the acknowledging contactor closed, relay RI will be energized by the drop in voltage across the coils of relay R3 over a circuit from the right hand side of the coils of relay R3, contact 4 of relay R2, contact 5 of relay R2, switch Y, secondary coil S of the receiver REC, coils of relay RI, to left-hand side of the coils of relay R3. The 01059 ing of'contact 2 of relay RI energizes relay R2. All of the circuits are now restored to normal.

The forestalling lever operated mechanism includes time delay means for opening the switch Z if the iorestalling lever is held operated for a predetermined time period usually approximately fifteen seconds. Opening of switch Z will release the electro-pneumatic valve EPV and cause an application of the brakes.

The mechanism known and so far described is such that the iorestalling lever may be operated at any speed of the locomotive and the automatic For the purpose of preventing an effective operation of the forestalling lever at speeds above a predator mined rate of speed, I have provided switches e and f in the iorestalling circuits including the switches X and Y, which may be operated by a solenoid RV, one terminal of the coil of which is connected to the positive side of the generator G and the other terminal of which is connected to a brush II cooperating with a commutator I2 which moves with an indicator hand I3 for indicating the speed on a dial I4. Cooperating also with the commutator is a brush I5 connected to the negative side of the generator G, the commutator being so located and of such length that M2 to open momentarily. Immediately vention disclosed claims.

at which the wayside signal block may be passed.

The iorestalling circuits will thereiore'open at switches e and 1 .when the speed of the train exceeds said predetermined speed and an operation oi the iorestalling lever will have no eiiect on the operation of the automatic train control apparatus.

A lamp PL may be connected in parallel with the solenoid RV. when the solenoid RV is energized and iorestalling is prevented, the PL pilot lamp is lighted.

In known constructions such as shown in the patent to Bond 2,099,100, November 10, 1937 and the patent to Porskievies 2,099,101, November 10, 1937, provision has been made to record the speed of the train on a tape 20 by means of a stylus 2i operated from the speedometer by a rack and pinion 22 and 23 as indicated. The tape may be fed by any suitable means proportionately to the distance traveled by the train. For the purpose of indicating an operation of the iorestalling lever on the tape,'I provide a stylus 25 on a rocking armature 28 of a solenoid 21 operated by current from the positive side of the generator G, over the coils of the solenoid 21, and over line 28 and switch 29 when closed by the iorestallin'g lever, to the negative side of the generator G.

In the modification disclosed mm. 2 the forestalling lever FL is provided with a pivoted looking bar 30 slidably mounted in a block 3| periorated to receive a locking pin 12 on an armature of a solenoid 33, the pin being pressed forwardly by a spring 34 through one of a plurality of apertures in the locking bar 30 when the solenoid is deenergized and withdrawn when the solenoid is energized over a circuit from the positive side of the generator G, contact 35 of relay 36 when cleenergized and coil of solenoid 33 to the negative side of the generator G. The circuit of the relay 38 is controlled by the brushes and commutator associated with the speedometer in the same manner as is the RV solenoid in the first modification. By means of these circuits the forestalling lever is released for operation only at speeds below the predetermined rate of speed. A pilot lamp PL may be connected in parallel with the relay 36.. When the relay 06 is energized and the solenoid 33 is deenergized and iorestaliing is prevented, the pilot light PL is lighted.

For the purpose of marking the tape at the speed at which the iorestalling lever is operated, I connect the coil of the solenoid 21 in a circuit which includes spring pressed contacts 40 and it and a bridging contact 42 carried by the end of the locking bar 30. By this means the stylus 25 is operated to indicate on the tape the speed of the train at which the iorestalling lever is operated. I

In describing my invention I have described briefly and illustrated diagrammatically a known system of train control with which my invention may be associated. It is to be understood however that the invention may be associated with other forms of train controls and that my invention is not limited to the modifications illustrated and described as this has been done merely for the purpose of disclosing my invention and is not to be considered limitative. It is to be understood\ that I reserve the right to make all such changes as fall within the principles of the ini a a and the scope of the appended Iclaim: v 1. In combination with a vehicle, a tape mounted on the. vehicle andmovable proportionately to the distance traveled by the vehicle, a marker associated with the tapepmeans automatically controlled by means along the wayside for reducing the speed oithe vehicle, and manual means for concurrentlyiorestalling an operation of said first mentioned meansand for operating said marker. j

2. In combination with a vehicle, a tape mounted on the vehicle and movable proportionately to the distance traveled by" the vehicle, a marker associated with the tape, means automatically controlled by means along the wayside for reducing the speed of the vehicle, and manual means for concurrently iorestalling an operation of said first mentioned means at speedsbelow a maximum predetermined speed only and for operating said marker at all speeds.

. 3. In combination with a vehicle, a tape mounted on the vehicle and movable proportionately to the distance traveled by the vehicle, a marker associated with the tape, manual means for operating said marker, means automatically controlled by means along the wayside for reducing the speed, of the vehicle, and means under control of the speed of the vehicle for locking said manual means against operation at speeds above a maximum predetermined rate of speed.

4. In combination with a vehicle, means on the vehicle responsive to wayside devices for auto matically reducing the speed oi the vehicle,

means for forestalling an operation of said first mentioned means at speeds below but not above a maximum predetermined speed, a signal, and speed controlled means operating said signal and rendering said Iorestaliing means inefiective at speeds above said maximum predetermined speed.

5. In combination with a vehicle, means on the vehicle responsive to wayside devices for automatically reducing the speed of the vehicle, means for forestalling an operation of said first mentioned means at speeds below but not above= a maximum predetermined speed, a signal, speedcontrolled means operating said signal and rendering said iorestalling means inefiective at speeds above said maximum predetermined speed, a distance tape operated by said vehicle, a marker for said tape, and manual means for operating said forestalling means and said marker.

6. In combination with a vehicle, means carried by the vehicle responsive to wayside devices for automatically reducing the speed of the vehicle, a iorestalling means for iorestalling an operation of said first mentioned means, manual means for operating said iorestalling means, 'a distance tape, means 'for locking said manual means against operation at speeds above a maximum predetermined speed, a marker associated with the tape, and means operated by said manual means for operating said marker.

7. In combination with a locomotive, a tape mounted on the locomotive and movable proportionately to the distance traveled by the locomotive, a marker associated with the tape ior recording any desired wayside information and its point of origin on the tape, and manual means for controlling the operation of the marker at will regardless oi the rate of speed of travel 01 the loco-. motive and of the tape.

8. In combination with a locomotive, a tape tor automatically reducing the speed or the vemounted on the locomotive and movable proporhicle, a iorestalllns means for iorestallin: the tionately to the distance traveled by the iocomooperation oi said first mentioned means, manual tive, speed recording means for recording the rate means for operating said torestalling means, a

l of travel 01 the locomotive in a predetermined distance tape, means for rendering said manual 8 zone of the tape, a marker associated with a diimeans ineiiective as to its operation of said toreferent zone of the tape for recording any desired stalling means at speeds above a maximum prewayside information and its point of oria'in on the determined speed, a marker associated with the tape, and manual means for operating said tape, and means operated by said manual means 10 market at will regardless of the rate oi! speed of for operating said marker upon each operation 10 travel of the locomotive and of the tape. 01' said manual means.

9. In combination with a vehicle. means car WM. BELL WAIT.

ried by the vehicle responsive to wayside devices 

